System and apparatus for pumping oil wells



p 1966 R. R. WATERMAN SYSTEM AND APPARATUS FOR PUMPING OIL WELLS Filed Sept. 24, 1962 INVEN TOR.

ATTOQH 5V RUSSELL B- 1414 TEQMAN 5% s; Jlamalam I8 I: I... f? i United States Patent 3,273,644 SYSTEM AND APPARATUS FOR PUMPING OIL WELLS Russell R. Waterman, Long Beach, Calif., assignor of ten percent to Vernon D. Beehler, Los Angeles, Calif.

Filed Sept. 24, 1962, Ser. No. 225,598

4 Claims. (Cl. 166-62) The invention relates to a system and apparatus for pumping oil wells and has particular reference to a means for maintaining a constant fluid level at the bottom of the hole in order to improve the effectiveness of the pumping whether the production be heated or pumped cold. The system and apparatus are, of course, directed primarily to those wells which are produced by pumping. Whether or not there may be some fluid or liquid drive, the system contemplates improving the flow of oil for production by the introduction, if need be, of a vacuum condition in the production well.

Considerable difliculty has been experienced in pumping hot fluid from oil wells because of the flashing of gases and high ends of the fluid when the pressure is lowered by the suction of the pump on the up stroke. In conjunction with this, it has been extremely difficult to maintain a proper level of liquid in the well over the formation to allow also for proper heating and also to allow for a liquid level condition in the well that will not retard the flow of oil from the formation into the casing. Heretofore, attempts at control have always been at the surface and subject entirely to constant attention of the operator to action of the pump, quantity of oil flow from the well, temperature conditions, and action of the pump itself. Where the discretion or even the skill of the operator must be counted upon for proper pumping conditions, there will always remain a personnel factor and an experience factor which can never be depended upon completely for proper performance. This is especially true where operators are inexperienced or even no more than prevented by local circumstances in the field from giving wells the attention needed for proper operation. In other words, unless the system is automatic, failures are bound to occur and in some instances such failures can be highly detrimental to proper performance. Although automatic and sometimes electronic indicating devices may be employed in a well to detect circumstances needing adjustment or change, such expedients are bothersome to install and operate, are prone to need servicing frequently, and also are unnecessarily costly.

An assortment of circumstances are responsible for poor performance. For example, a proper pump in a Well may lower the liquid head too far under circumstances where the bottom of the hole is being heated to allow for proper heating due to lack of liquid for rapid heat transfer in the well. Under other circumstances, the pump may fail to lower the liquid level low enough to allow suflioient pressure in the casing for oil to flow into the casing properly.

Among the objects of the invention is to provide a system and apparatus capable of maintaining any desired constant liquid level which may be necessary for the proper heating of an oil well and accordingly the proper pumping of such a heated oil well.

Another object of the invention is to provide a new and improved system and apparatus for extracting by pumping all of the liquid which the well will produce without lowering the surface of the liquid below a desired level.

Another object of the invention is to provide a new and improved system and apparatus which will eliminate typicas gas locking of the fluid pumping means.

Still another object of the invention is to provide a new and improved system and apparatus capable of creating a desired vacuum in the casing thereby to obtain maximum production making use of the same pumping unit employed to pump fluid from the well whether production is from a single isolated well or from a pattern of wells in a field where on occasions a hot or cold fluid drive may be created.

Still another object of the invention is to provide a new and improved system and apparatus which will cause automatic priming of the pump at least after a short period of time under such occasions where a gas lock might occur due to a quick rise of fluid in a gas anchor casing.

Still another object of the invention is to provide a new and improved system and apparatus which can be Withdrawn from time to time as needed in order to effectively flush the fluid control portion of the apparatus by simple, effective means without it being necessary to actually withdraw equipment entirely out of the well or even entirely out of the bottom of the well.

With these and other objects in view, the invention consists in the construction, arrangement and combination of the various parts of the device, whereby the objects contemplated are attained, as hereinafter set forth, pointed out in the appended claims and illustrated in the accompanying drawings.

In the drawings:

FIGURE 1 is a longitudinal, sectional, foreshortened view of a typical installation of equipment in a well whereby the system may be practiced.

FIGURE 2 is a foreshortened, longitudinal, sectional view of one form of device usable in an installation like that shown in FIGURE 1.

FIGURE 3 is a cross-sectional view on the line 33 of FIGURE 2.

FIGURE 4 is a cross-sectional view on the line 44 of FIGURE 2.

FIGURE 5 is a schematic representation of a field showing the installation of two wells penetrating the same production formation.

FIGURE 6 is a longitudinal, sectional, foreshortened view of a second form of the invention.

FIGURE 7 is a cross-sectional view taken on the line 77 of FIGURE 6.

FIGURE 8 is a cross-sectional view taken on the line 88 of FIGURE 6.

In an embodiment of the invention chosen for the purpose of illustration, there is shown an oil well 10 extending from the surface 11 of the ground through ordinary strata 12 into a zone or formation 13 containing oil. A casing 14 extends into the well and has a sealed cap 15 at the surface. Below the casing and extending through the formation is a perforated liner 16 of the custom sort which reaches into the sump 17 at the bottom which is sealed as by means of cement 18.

Extending into the well is a pump line 19 of the usual sort manipulated by a tropical reciprocating pump arm 20 which manipulates a sucker rod 21.

On the assumption that the well may be a heated well, there is shown extending into the well a steam line 22 such as that illustrated and described in one or all of Patent Nos. 2,705,535; 2,828,821; and 3,028,916. Reference is also made to copending application Serial No. 180,147, filed March 16, 1962, of which this is a continuation-inpart.

To assist in completing, in this application, an understanding of the heating portion of the system, there is shown, at the top of the steam line, gages 23 and 24 separated by a valve 25. Steam from a suitable source flows through a pipe section 26 to the steam line.

On the assumption that for this particular installation by way of example, the zone or formation is 2,000 feet below the surface 11, it will also be assumed that the depth of the formation or zone is 70 feet. The bottom 50 feet of the steam line is considered as the heating jacket and at the bottom of this is an orifice fitting 27 below which is a condensing section 28 which may be about 20 feet long inasmuch as 20 feet is a customary ilength for pipe sections. Good practice suggests that the bottom of the condensing section be about feet above the bottom of the well. In an installation of this kind, it can be assumed that liquid production should be maintained in the bottom of the well so as to be constantly at a level 30. This is suggested in order that substantially the entire length of the heating jacket at the bottom of the steam line will be constantly immerse-d in a liquid bath. An object of the system and equipment here under consideration involves keeping the fluid level 30 at the desired level, irrespective of how the pump may be manipulated from time to time and irrespective of what attention may be given to it by an operator.

At the bottom of the production tubing heretofore identiiied as a product-ion line 19, there is provided a stand pipe section 31 which is substantially immersed in a reservoir of production fluid, the top of which has previously been identified as the level 30. Neglecting for practical purposes the location of the stand pipe sect-ion below sea level, the maximum effective length of the stand pipe section can be limited to about 33 feet. The section terminates at the bottom in a special foot coupling 3-2. The stand pipe section may properly be defined as a hollow casing having a sump chamber 33 therein. Adjacent the top of the casing is a special seat coupling 34 on the inner surface 35 of which is a series of seals 36. Immediately below the seat coupling is a gas vent 37 and below the gas vent is a pump inflow port 38 into which liquid from the reservoir flows ino the sump 33. The pump inflow port 38 will be located at the level 30 which is desired to be maintained.

A jacket 40 comprising a sump filling portion extends throughout substantially the entire length of the sump chamber 33. The outside diameter of the jacket is made relatively large as compared with the inside diameter of the sump chamber so that only a relatively small volume of production fluid flowing into the chamber from the inflow port will be needed to fill the sump chamber.

Extending below the jacket is in insert section 41 which is hollow and adjacent the lower end of which are pump inlet ports 42, adjacent the inside end of which is located an inflow check 43. Above the hollow insert section 41 is an inlet pump chamber 44 separated by a seal 45 from a pump chamber 46. A pump piston 47 is sl-idably mounted within the seal 45 and is provided at the bottom with an inlet check valve 48 located between an inlet passage 49 and branch passages 50 which communicate with the pump chamber 46. The sucker rod 21 is fastened to the piston 47 so as to reciprocate the piston throughout the vertical length of the stroke.

The pump acts in a fashion familiar to pump mechanisms in that as the piston is reciprocated in a vertical direction upwardly the inflow check 43 is unseated and the inlet check valve 48 is seated. Accordingly, fluid flows from the sump through the pump inlet ports 42 into the inlet chamber 44 filling the chamber 44. When the piston then moves downwardly the inflow check 43 seats and fluid in the inlet chamber 44 unseats the inlet check valve 48 whereupon the fluid flows through the inlet passages 50 into the pump chamber 46. The upward stroke is then repeated sucking more liquid into the inlet chamber 44 followed by forcing some of this liquid into the pump chamber 46. As operation continues, fluid in the pump chamber 46 is gradually forced upwardly through the pump line 19 to the surface where it flows from the production line in the customary fashion.

As a clean-out convenience, the foot coupling 32 is provided with a flush passage 55 within which a lower end 56 of the insert section 41 fits with a relatively snug sliding fit. The lower end '56 normally closes the flush passage while operation is in progress. Should it be desired to flush the stand pipe section, the sucker rod 21 is lifted elevating the pump piston 47 until it engages a sleeve 57 sealed within the seat coupling 34 whereupon the jacket 40 is lifted, lifting with it the insert section 41 and the lower end 56 until it is removed from the flush passage '55. At this point, any fluid in the sump 33 will flow outwardly through the flush passage, flushing out any debris or undesired semifluids. After flushing has been accomplished, the piston 47 and accompanying insert section 41 and lower end 56 is again lowered until the lower end 56 again closes the flush passage 55 after which pumping is resumed.

For the system and pumping apparatus to be as effective as desired, the pump capacity should be made substantially greater than the maximum capacity needed to pump out all of the production fluid which will flow into the reservoir at the bottom of the well. By making the pump an overcapacity pump by three, four, five, or six times, except for a slightly greater operating demand the pump works in a normal fashion. Overpumping can never take place because the level of the pump inflow port 38 at the top of the stand pipe section 31 determines the .level 30 and hence this will remain constant at whatever level is set. Should no more fluid flow into the sump and the pump continue to pump, it will merely tend to generate a vacuum above the level 30. This lowering of pressure within the well can be depended upon to induce a greater flow of production from the formation or zone into the bottom of the well. This low pressure condition is not only useful in a single well which is being heated but is equally useful when no heating is taking place and the desire is only to hold the liquid level 30 at a proper level for cold production. The cold production will also be improved by the low presure condition.

Further still, when, in a system like that illustrated in FIGURE 5, there is a flood Well 60 for the introduction of hot or cold water into the zone, creation of a low pressure condition like that just described by what for want of a better term, can be designated as overpumping. The low pressure condition at the production level will combine with the high pressure condition in the flood well thereby to induce to an even greater degree the drive through the zone '13 to the production well where a portion of the overcapacity of the pump may be made use of automatically in increasing the pumping production as the flow of production induced by the differential pressure condition increases the production of the well. This circumstance hold-s equally for hot water flooding, steam heating, or cold water flooding and pumping or any combination thereof. Some special conditions, of course, will be better applicable depending on whether the production well is a heated well or a cold well in that for a hot well a good vacuum condition to maintain will be from about 20 to 22 inches whereas in a cold well the condition should be appreciably higher.

Further still, where merely the pressure differential portion of the system is to be taken advantage of, a variety of different kinds of pumps may be employed to generate the low pressure condition. The pump involved will then not need to be reestricted to the piston-type pump described in detail for other advantageous elements in the system.

In a modified form of the pumping apparatus illustrated in FIGURES 6, 7, and 8, there is shown a stand pipe section 65 having a length approximately about 33 feet but in any event a length sufiicient to extend about 30 to 35 feet into the reservoir below the level 30 if the reservoir is that deep. Should the reservoir be of depth less than 30 to 35 feet, the stand pipe section will, of course, be made no longer than necessary to reach to an elevation close to the bottom of the Well. At the top of the stand pipe section is a special coupling 66 to which is attached production tubing 67. The stand pipe section provides a sump chamber 68 near the top of which is a pump inflow port 69 and a gas vent 70, if preferred.

In this form of device, a jacket 71 comprising a sump filling portion threadedly attached to the special coupling 66 extends downwardly for an appreciable distance into the sump chamber. At the bottom of the jacket, centering fins 72 locate the jacket on the axial center line of the stand pipe section 65. A seat coupling 73 at the bottom of the jacket 71 is provided with seals 74 within which is mounted a sleeve 75. Extending downward from the sleeve 75 is a pump jacket 76 within which is located a pump piston 77. The pump piston is reciprocated in a vertical direction in the customary fashion by a sucker rod 78. The last described pump actuates in the usual fashion much as described in connection with the first identified form drawing liquid from the sump through pump inlet ports 79 from which the liquid is passed to the surface by the commonly understood pumping action. Here again there is provided a foot coupling 80 having a flush passage 81 therein normally closed by a lower insert end 82 of the pump jacket which can be lifted and withdrawn to open the flush passage for flushing purposes when occasion requires and thereafter be lowered to close the passage.

In the last defined form of the invention, the pump jacket can be made appreciably shorter in that it need be little longer than the length of the piston 77 which can be kept relatively short, taking into consideration no more than the stroke of the pump. Here also the stand pipe section 65 which is of relatively large diameter need be made of that relatively large diameter only for the depth of the zone and no longer, terminating in the production tubing 67 at the upper end which can be kept relatively small, depending upon the capacity needed to pass all of the production of the well.

By employment of the system and apparatus hereinabove described, it will be clear that the liquid level in the well can be fixed depending upon circumstances and once fixed is automatically maintained at the selected level. No amount of manipulation of pump action from the surface will alter the level. The only way to change the level is to actually change the height of the stand pipe section in the well and this will be done only as a special adjustment when proper pumping is initially determined by performance of the well in a heated condition, or cold condition depending upon how the well is to be operated. Further still, even though the temperature of the heating operation may vary inadvertently, where that temperature is initially set at an adequate amount, should there be slightly more production produced by the operation, it will merely fill the sump at a more rapid rate and be pumped out more rapidly by the overcapacity pump. Should heating fall off and the production flow into the well fall-off, the liquid level will still be maintained because it cannot be pumped below the level of the pump inlet port 38.

In the event that there should be a vapor lock on the pump due to slight overpumping, this normally can be very quickly remedied because of the relatively low volume of that portion of the sump which surrounds the jacket 40. In practice, the space between the exterior of the jacket 40 and the interior of the stand pipe section 31 can be kept from about one-quarter inch to three eighths inch, namely, a spacing appreciably less proportionately than that shown in the drawings for the purpose of keeping the volume as low as practical. Promptness of the pump priming action is by this means made certain.

While the invention has herein been shown and described in what is conceived to be the most practical and preferred embodiment, it is recognized that departures maybe made therefrom within the scope of the invention, which is not to be limited to the details dis-closed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent devices.

Having described the invention, what is claimed as new in support of Letters Patent is:

1. A system for heating and pumping an oil well from a reservoir of production fluid at a production zone comprising a heating line extending from ground surface into the well and having a heat exchanger section extending into the reservoir from a location adjacent the top to a location adjacent the bottom thereof, a production tubing line extending from the surface into the well and having a stand pipe section extending into said reservoir, said heat exchanger being separate from and located between said stand pipe section and the adjacent circumference of the well, said stand pipe section comprising a hollow casing having a sump chamber therein, said stand pipe section having adjacent the upper end of the sump chamber and adjacent the upper end of said reservoir a production inflow port, said inflow port being substantially at the level of the top of said heat exchanger, and pumping means in communication with the lower end of the sump and connected to said production line whereby to pass production fluid from the sump to the surface.

2. A system for heating and pumping an oil well from a reservoir of production fluid at a production zone comprising a heating line extending from ground surface into the well and having a heat exchanger section extending into the reservoir from adjacent the upper level of the zone to adjacent the lower level of the zone, a production tubing line extending from the surface into the well and having a stand pipe section extending into said reservoir, said heat exchanger section being separate from the stand pipe section and located between said stand pipe section and the adjacent circumference of the well, said stand pipe section comprising a substantially cylindrical casing having a sump chamber therein, said stand pipe section having adjacent the upper end of the sump chamber and adjacent the upper end of said reservoir a production inflow port and a gas vent port above the upper end of said reservoir, pumping means in said sump adjacent the lower end thereof and connected to said production line and a pump inlet port located on the pumping means and adjacent the bottom of said sump chamber, whereby to pass production fluid from the sump only to the surface.

3. A system for heating and pumping an oil well from a reservoir of production fluid at a production zone comprising a heating line extending from ground surface into the Well and having a heat exchanger section extending into the reservoir from adjacent the upper level of the zone to adjacent the lower level of the zone, a production tubing line extending from the surface into the well and having a stand pipe section extending into said reservoir, said stand pipe section comprising a substantially cylindrical casing having a sump chamber therein, said production line including a sump filling portion extending throughout the length of said sump and a pump section at a location below the lower end of said sump filling portion, said sump filling portion having an exterior diameter only slightly smaller than the interior diameter of said stand pipe section whereby to provide a stand pipe csapacity of relatively low volume as compared with the volume of the reservoir, a seal between the sump filling portion and the stand pipe section above the upper level of the zone, said stand pipe section having a flushing hole at the bottom and a plug on the pump section removably seated in said hole in closing position therein, said stand pipe section having adjacent the top of said stand pipe section and adjacent the upper level of said reservoir a production inflow port and a gas vent therefrom, said inlet being adjacent the top of said heat exchanger, said pump section having a pump inflow port to the interior thereof in communication with said pump section adjacent the bottom and with said stand pipe section, a pump piston adjacent the bottom of said pump section and a pump rod extending from the piston through said production tubing to the surface.

4. A system for heating and pumping an oil well from 7 a reservoir of production fluid at a production zone comprising a heating line extending from ground surface into the Well and having a heat exchanger section extending into the reservoir from adjacent the upper level of the zone to adjacent the lower level of the zone, a production tubing line extending from the surface into the well and having a stand pipe section extending into said reservoir at the side of and separate from said heat exchanger section, said stand pipe section comprising a substantially cylindrical casing having a sump chamber therein, said production line including a sump filling portion in said sump and a pump casing extending below the lower end of said sump filling portion, a fluid tight connection between the sump filling portion and the stand pipe section at about the upper level of the zone, said stand pipe section having a flushing hole at the bottom and a plug on the pump casing removably seated in said hole in closing position therein, said stand pipe section having a production inflow port adjacent the top of said stand pipe section and adjacent the upper level of said reservoir and 8 having a. gas vent therefrom adjacent said inflow port, said pump casing having a pump inflow port to the interior thereof in communication with the bottom of said pump casing and with said stand pipe section, a pump piston in said pump casing and a pump rod extending from the piston through said production tubing to the surface.

References Cited by the Examiner UNITED STATES PATENTS 171, 563 12/1875 Hardison 16662 993,520 5/1911 Hahn 103-179 1,237,139 9/1917 Yeomans 166-11 2,808,110 10/1957 Spitz 166-61 2,874,780 2/ 1959 Gertzen 166-105 CHARLES E. OCONNELL, Primary Examiner. T. A. ZALENSKI, Assistant Examiner. 

1. A SYSTEM FOR HEATING AND PUMPING AN OIL WELL FROM A RESERVOIR OF PRODUCTION FLUID AT A PRODUCTION ZONE COMPRISING A HEATING LINE EXTENDING FROM GROUND SURFACE INTO THE WELL AND HAVING A HEAT EXCHANGER SECTION EXTENDING INTO THE RESERVOIR FROM A LOCATION ADJACENT THE TOP TO A LOCATION ADJACENT THE BOTTOM THEREOF, A PRODUCTION TUBING LINE EXTENDING FROM THE SURFACE INTO THE WELL AND HAVING A STAND PIPE SECTION EXTENDING INTO SAID RESERVOIR, SAID HEAT EXCHANGER BEING SEPARATE FROM AND LOCATED BETWEEN SAID STAND PIPE SECTION AND THE ADJACENT CIRCUMFERENCE OF THE WELL, SAID STAND PIPE SECTION COMPRISING A HOLLOW CASING HAVING A SUMP CHAMBER THEREIN, SAID STAND PIPE SECTION HAVING ADJACENT THE UPPER END OF THE SUMP CHAMBER AND ADJACENT THE UPPER END OF SAID RESERVOIR A PRODUCTION INFLOW PORT, SAID INFLOW PORT BEING SUBSTANTIALLY AT THE LEVEL OF THE TOP OF SAID HEAT EXCHANGER, AND PUMPING MEANS IN 